He’s the travel agent who booked the trip. Nobody buys a one-way ticket for a wife who’s coming back.
A man on a park bench reads a newspaper story headlined “Death at Sea”. A woman has gone overboard on a cruise. He knows at once that she was murdered. How?
Give me a hintThe hint
It’s to do with his job.
Reveal the answerHide the answer
He’d sold her husband a return ticket and her a single
Source: Agnes Rogers, How Come?, 1953